summaryrefslogtreecommitdiff
path: root/notes.c
AgeCommit message (Collapse)Author
2010-02-14Refactor notes concatenation into a flexible interface for combining notesJohan Herland
When adding a note to an object that already has an existing note, the current solution is to concatenate the contents of the two notes. However, the caller may instead wish to _overwrite_ the existing note with the new note, or maybe even _ignore_ the new note, and keep the existing one. There might also be other ways of combining notes that are only known to the caller. Therefore, instead of unconditionally concatenating notes, we let the caller specify how to combine notes, by passing in a pointer to a function for combining notes. The caller may choose to implement its own function for notes combining, but normally one of the following three conveniently supplied notes combination functions will be sufficient: - combine_notes_concatenate() combines the two notes by appending the contents of the new note to the contents of the existing note. - combine_notes_overwrite() replaces the existing note with the new note. - combine_notes_ignore() keeps the existing note, and ignores the new note. A combine_notes function can be passed to init_notes() to choose a default combine_notes function for that notes tree. If NULL is given, the notes tree falls back to combine_notes_concatenate() as the ultimate default. A combine_notes function can also be passed directly to add_note(), to control the notes combining behaviour for a note addition in particular. If NULL is passed, the combine_notes function registered for the given notes tree is used. Signed-off-by: Johan Herland <johan@herland.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-02-14Notes API: Allow multiple concurrent notes trees with new struct notes_treeJohan Herland
The new struct notes_tree encapsulates access to a specific notes tree. It is provided to allow callers to make use of several different notes trees simultaneously. A struct notes_tree * parameter is added to every function in the notes API. In all cases, NULL can be passed, in which case the fallback "default" notes tree (default_notes_tree) is used. Signed-off-by: Johan Herland <johan@herland.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-02-14Notes API: write_notes_tree(): Store the notes tree in the databaseJohan Herland
Uses for_each_note() to traverse the notes tree, and produces tree objects on the fly representing the "on-disk" version of the notes tree with appropriate fanout. Signed-off-by: Johan Herland <johan@herland.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-02-14Notes API: for_each_note(): Traverse the entire notes tree with a callbackJohan Herland
This includes a first attempt at creating an optimal fanout scheme (which is calculated on-the-fly, while traversing). Signed-off-by: Johan Herland <johan@herland.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-02-14Notes API: get_note(): Return the note annotating the given objectJohan Herland
Created by a simple cleanup and rename of lookup_notes(). Signed-off-by: Johan Herland <johan@herland.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-02-14Notes API: remove_note(): Remove note objects from the notes tree structureJohan Herland
This includes adding internal functions for maintaining a healthy notes tree structure after removing individual notes. Signed-off-by: Johan Herland <johan@herland.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-02-14Notes API: add_note(): Add note objects to the internal notes tree structureJohan Herland
Signed-off-by: Johan Herland <johan@herland.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-02-14Notes API: init_notes(): Initialize the notes tree from the given notes refJohan Herland
Created by a simple refactoring of initialize_notes(). Also add a new 'flags' parameter, which is a bitwise combination of notes initialization flags. For now, there is only one flag - NOTES_INIT_EMPTY - which indicates that the notes tree should not auto-load the contents of the given (or default) notes ref, but rather should leave the notes tree initialized to an empty state. This will become useful in the future when manipulating the notes tree through the notes API. Signed-off-by: Johan Herland <johan@herland.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-02-14Notes API: get_commit_notes() -> format_note() + remove the commit restrictionJohan Herland
There is really no reason why only commit objects can be annotated. By changing the struct commit parameter to get_commit_notes() into a sha1 we gain the ability to annotate any object type. To reflect this in the function naming as well, we rename get_commit_notes() to format_note(). This patch also fixes comments and variable names throughout notes.c as a consequence of the removal of the unnecessary 'commit' restriction. Signed-off-by: Johan Herland <johan@herland.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-02-14Minor cosmetic fixes to notes.cJohan Herland
Signed-off-by: Johan Herland <johan@herland.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-12-03Fix crasher on encountering SHA1-like non-note in notes treeJohan Herland
When loading a notes tree, the code primarily looks for SHA1-like paths whose total length (discounting directory separators) are 40 chars (interpreted as valid note entries) or less (interpreted as subtree entries that may in turn contain note entries when unpacked). However, there is an additional condition that must hold for valid subtree entries: They must be _tree_ objects (duh). This patch adds an appropriate test for this condition, thereby fixing the crash that occured when passing a non-tree object to the tree-walk API. The patch also adds another selftest verifying correct behaviour of non-notes in note trees. Signed-off-by: Johan Herland <johan@herland.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-10-20Refactor notes code to concatenate multiple notes annotating the same objectJohan Herland
Currently, having multiple notes referring to the same commit from various locations in the notes tree is strongly discouraged, since only one of those notes will be parsed and shown. This patch teaches the notes code to _concatenate_ multiple notes that annotate the same commit. Notes are concatenated by creating a new blob object containing the concatenation of the notes in question, and replacing them with the concatenated note in the internal notes tree structure. Getting the concatenation right requires being more proactive in unpacking subtree entries in the internal notes tree structure, so that we don't return a note prematurely (i.e. before having found all other notes that annotate the same object). As such, this patch may incur a small performance penalty. Suggested-by: Sam Vilain <sam@vilain.net> Re-suggested-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Johan Herland <johan@herland.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-10-20Teach the notes lookup code to parse notes trees with various fanout schemesJohan Herland
The semantics used when parsing notes trees (with regards to fanout subtrees) follow Dscho's proposal fairly closely: - No concatenation/merging of notes is performed. If there are several notes objects referencing a given commit, only one of those objects are used. - If a notes object for a given commit is present in the "root" notes tree, no subtrees are consulted; the object in the root tree is used directly. - If there are more than one subtree that prefix-matches the given commit, only the subtree with the longest matching prefix is consulted. This means that if the given commit is e.g. "deadbeef", and the notes tree have subtrees "de" and "dead", then the following paths in the notes tree are searched: "deadbeef", "dead/beef". Note that "de/adbeef" is NOT searched. - Fanout directories (subtrees) must references a whole number of bytes from the SHA1 sum they subdivide. E.g. subtrees "dead" and "de" are acceptable; "d" and "dea" are not. - Multiple levels of fanout are allowed. All the above rules apply recursively. E.g. "de/adbeef" is preferred over "de/adbe/ef", etc. This patch changes the in-memory datastructure for holding parsed notes: Instead of holding all note (and subtree) entries in a hash table, a simple 16-tree structure is used instead. The tree structure consists of 16-arrays as internal nodes, and note/subtree entries as leaf nodes. The tree is traversed by indexing subsequent nibbles of the search key until a leaf node is encountered. If a subtree entry is encountered while searching for a note, the subtree is unpacked into the 16-tree structure, and the search continues into that subtree. The new algorithm performs significantly better in the cases where only a fraction of the notes need to be looked up (this is assumed to be the common case for notes lookup). The new code even performs marginally better in the worst case (where _all_ the notes are looked up). In addition to this, comes the massive performance win associated with organizing the notes tree according to some fanout scheme. Even a simple 2/38 fanout scheme is dramatically quicker to traverse (going from tens of seconds to sub-second runtimes). As for memory usage, the new code is marginally better than the old code in the worst case, but in the case of looking up only some notes from a notes tree with proper fanout, the new code uses only a small fraction of the memory needed to hold the entire notes tree. However, there is one casualty of this patch. The old notes lookup code was able to parse notes that were associated with non-SHA1s (e.g. refs). The new code requires the referenced object to be named by a SHA1 sum. Still, this is not considered a major setback, since the notes infrastructure was not originally intended to annotate objects outside the Git object database. Cc: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Johan Herland <johan@herland.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-10-20Teach notes code to free its internal data structures on requestJohan Herland
There's no need to be rude to memory-concious callers... This patch has been improved by the following contributions: - Junio C Hamano: avoid old-style declaration Signed-off-by: Junio C Hamano <gitster@pobox.com> Signed-off-by: Johan Herland <johan@herland.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-10-20Add flags to get_commit_notes() to control the format of the note stringJohan Herland
This patch adds the following flags to get_commit_notes() for adjusting the format of the produced note string: - NOTES_SHOW_HEADER: Print "Notes:" line before the notes contents - NOTES_INDENT: Indent notes contents by 4 spaces Suggested-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Johan Herland <johan@herland.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-10-20Speed up git notes lookupJohannes Schindelin
To avoid looking up each and every commit in the notes ref's tree object, which is very expensive, speed things up by slurping the tree object's contents into a hash_map. The idea for the hashmap singleton is from David Reiss, initial benchmarking by Jeff King. Note: the implementation allows for arbitrary entries in the notes tree object, ignoring those that do not reference a valid object. This allows you to annotate arbitrary branches, or objects. This patch has been improved by the following contributions: - Junio C Hamano: fixed an obvious error in initialize_hash_map() Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Johan Herland <johan@herland.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-10-20Introduce commit notesJohannes Schindelin
Commit notes are blobs which are shown together with the commit message. These blobs are taken from the notes ref, which you can configure by the config variable core.notesRef, which in turn can be overridden by the environment variable GIT_NOTES_REF. The notes ref is a branch which contains "files" whose names are the names of the corresponding commits (i.e. the SHA-1). The rationale for putting this information into a ref is this: we want to be able to fetch and possibly union-merge the notes, maybe even look at the date when a note was introduced, and we want to store them efficiently together with the other objects. This patch has been improved by the following contributions: - Thomas Rast: fix core.notesRef documentation - Tor Arne Vestbø: fix printing of multi-line notes - Alex Riesen: Using char array instead of char pointer costs less BSS - Johan Herland: Plug leak when msg is good, but msglen or type causes return Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Thomas Rast <trast@student.ethz.ch> Signed-off-by: Tor Arne Vestbø <tavestbo@trolltech.com> Signed-off-by: Johan Herland <johan@herland.net> Signed-off-by: Junio C Hamano <gitster@pobox.com> get_commit_notes(): Plug memory leak when 'if' triggers, but not because of read_sha1_file() failure
2009-02-11Revert "Merge branch 'js/notes'"Junio C Hamano
This reverts commit 7b75b331f6744fbf953fe8913703378ef86a2189, reversing changes made to 5d680a67d7909c89af96eba4a2d77abed606292b.
2009-01-14git-notes: fix printing of multi-line notesTor Arne Vestbø
The line length was read from the same position every time, causing mangled output when printing notes with multiple lines. Also, adding new-line manually for each line ensures that we get a new-line between commits, matching git-log for commits without notes. Signed-off-by: Tor Arne Vestbø <tavestbo@trolltech.com> Acked-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-01-12Speed up git notes lookupJohannes Schindelin
To avoid looking up each and every commit in the notes ref's tree object, which is very expensive, speed things up by slurping the tree object's contents into a hash_map. The idea fo the hashmap singleton is from David Reiss, initial benchmarking by Jeff King. Note: the implementation allows for arbitrary entries in the notes tree object, ignoring those that do not reference a valid object. This allows you to annotate arbitrary branches, or objects. [jc: fixed an obvious error in initialize_hash_map()] Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-12-21Introduce commit notesJohannes Schindelin
Commit notes are blobs which are shown together with the commit message. These blobs are taken from the notes ref, which you can configure by the config variable core.notesRef, which in turn can be overridden by the environment variable GIT_NOTES_REF. The notes ref is a branch which contains "files" whose names are the names of the corresponding commits (i.e. the SHA-1). The rationale for putting this information into a ref is this: we want to be able to fetch and possibly union-merge the notes, maybe even look at the date when a note was introduced, and we want to store them efficiently together with the other objects. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>